In an ink jet recording head, voltage having drive waveform which is applied to the head has to be set properly to make the discharge speed or discharge amount of ink drops discharged from nozzles of the head constant. Concretely, the voltage having the drive waveform has to be properly set according to individual difference of heads, ink viscosity, temperature, and the like.
As a power supply circuit setting the voltage having the drive waveform which is applied to a head, for example, a DC-DC converter converting DC voltage to DC voltage having another voltage value is used.
In the case of supplying power from the DC-DC converter to an ink jet recording head, a capacitor having relatively large capacity is connected between the DC-DC converter and the head. The capacitor is provided to address the load fluctuation. Particularly, in recent years, there is tendency that the number of nozzles of a head is increasing and the capacity of a capacitor which is connected has to be increased in proportion to the increase in the number of nozzles.
Patent Literature 1 discloses a technique of supplying drive voltage for performing recording operation by driving an ink jet recording head via a DC-DC converter to the head. FIG. 3 of Patent Literature 1 illustrates the configuration that a smoothing capacitor for preventing load fluctuation is connected to a recording head.